[GreenKeys] Off topic you say? Here's your off topic!

[tony.podrasky]

GM OMs;

Hey Gil -

I did something like that about 18 years ago.

o I got a digital clock that receives WWVB (kinda like
   Heathkit's "Most Accurate Clock".

o Connected it to my main host computer with the DB-9
   serial port.

o Wrote a driver to poll it every 3 hours.

o Set up main host as a XNTPD time server.

o Set all the other hosts to receive time from it.

It's been running ever since.

I keep my internet connection shutdown except when I
want to get on the internet so using an internet
time server wouldn't work for me.

The only problem I have is that some of my computers
are so old that they are running the pre congress-knows-best
DST modules and it isn't worth the work to update them,
so twice a year, for about 2-3 weeks, some of them are
an hour off - PRECISELY.

UE,
W6ESE - tony
NNNN
ZCZC


On 04/22/2013 04:58 AM, Frank Carraro wrote:
>     -----Original Message-----
>     *From:* gil at baudot.net [mailto:gil at baudot.net]
>     *Sent:* Sunday, April 21, 2013 8:22 PM
>     *To:* Frank Carraro; greenkeys at mailman.qth.net
>     *Subject:* RE: [GreenKeys] Off topic you say? Here's your off topic!
>
>     Hey Frank:
>
>     Kinda interesting that you would mention synchronizing clocks, since
>     I want to do the same thing.  I am in the middle of a design that
>     has an ethernet port and a wireless transceiver.  The ethernet part
>     is using microchip's tcpip stack with my code wrapped around it.
>     Besides connecting sockets for data I also want to be able to pull
>     time and date from one of the many time services on the net.  In
>     addition to keeping my own rtc updated, I want to broadcast a
>     time/date update around the building, for clocks and such to use.  I
>     plan to use a nice little fcc-certified 2.4GHz module, also from
>     microchip, for the wireless section.  One possible-gotcha is that
>     the fcc does not seem to want any "periodic" data sent on their
>     precious license-free bands (eg: 315, 418, 433, 2.4G), so I plan to
>     randomize the timing of the low-rep-rate update broadcasts.  I also
>     want to have temperature and other stuff returned, in an equally
>     random fashion.  An rf collision here and there won't matter, as
>     another update will be coming.
>
>     Now you want an hourly update, but then you also have cable
>     available.  You could probably just get time from the nearest
>     computer, with a little code and a usb-serial adapter and a little
>     circuitry to drive your cables and clock solenoids.  Don't forget
>     the freewheeling diode across the solenoid coil.
>
>     gil

-- 
Tony J. Podrasky | Latin:   Estne tibi forte magna
                  |          feles fulva a planissima?
                  | English: Do you by any chance happen to own
                  |          a large, yellowish, very flat cat?